R-T-B based permanent magnet

Abstract

An R-T-B based permanent magnet wherein R is one or more rare earth elements, T is Fe and Co, and B is boron. The R-T-B based permanent magnet includes M, C and N, wherein M is two or more selected from Cu, Ga, Mn, Zr, and Al, and includes at least Cu and Ga. A total content of R is ≥29.0 and ≤33.5 mass %, Co content is ≥0.10 and ≤0.49 mass %, B content is ≥0.80 and ≤0.96 mass %, a total content of M is ≥0.63 and ≤4.00 mass %, Cu content is ≥0.51 and ≤0.97 mass %, Ga content is ≥0.12 and ≤1.07 mass %, C content is ≥0.065 and ≤0.200 mass %, N content is ≥0.023 and ≤0.323 mass %, and Fe is a substantial balance.

What is claimed is: 
     
       1. An R-T-B based permanent magnet in which R is one or more rare earth elements, T is a combination of Fe and Co, and B is boron,
 wherein the R-T-B based permanent magnet comprises M, C, and N, 
 M is three or more selected from Cu, Ga, Mn, Zr, and Al, and comprises at least Cu, Ga, and Mn, and 
 relative to 100 mass % of the R-T-B based permanent magnet:
 a total content of R is 29.0 mass % or more and 33.5 mass % or less, 
 Co content is 0.10 mass % or more and 0.49 mass % or less, 
 B content is 0.80 mass % or more and 0.96 mass % or less, a total content of M is 0.66 mass % or more and 4.00 mass % or less, 
 Cu content is 0.51 mass % or more and 0.97 mass % or less, 
 Ga content is 0.12 mass % or more and 1.07 mass % or less, 
 Mn content is 0.03 mass % or more and 0.08 mass % or less, 
 C content is 0.065 mass % or more and 0.200 mass % or less, 
 N content is 0.023 mass % or more and 0.323 mass % or less, and 
 Fe is a substantial balance. 
 
 
     
     
       2. The R-T-B based permanent magnet according to  claim 1 , wherein Zr content is 0.15 mass % or more and 0.42 mass % or less. 
     
     
       3. The R-T-B based permanent magnet according to  claim 1 , wherein Al content is 0.08 mass % or more and 0.41 mass % or less. 
     
     
       4. The R-T-B based permanent magnet according to  claim 1 , wherein a total content of Co, Cu, and Al is 1.00 mass % or more and 2.00 mass % or less. 
     
     
       5. The R-T-B based permanent magnet according to  claim 1 , wherein a total content of Co and Mn is 0.40 mass % or more and 1.00 mass % or less.